1. Field of the Invention
The present invention relates to safety devices used during building construction, maintenance, and repair. More particularly, the present invention relates to safety devices used by workers to secure themselves during building construction, maintenance, and repair. Even more particularly, the present invention relates to safety devices that can be used by more than one worker concurrently to secure themselves from falls through open spaces or from roofs or other edges during building construction, maintenance, and repair.
2. Prior Art
The Occupational Safety and Health Administration, as well as common sense, requires that workers near a hazardous open space be protected against possible falls into the open space. For instance, roofers must be secured against falling off the roof, or, if working near a hole in the roof, against falling into the hole. A technique widely used today in the construction industry involves securing a length of rope to a worker at one end and to a stanchion of some sort at the other end, the stanchion being attached to a surface such as a roof being worked on. These ropes frequently become tangled, caught by other workers or equipment, or cut, thus increasing both danger and inconvenience to the worker while reducing comfort and productivity because of having to work around the ropes.
Several patents have addressed the idea of directly or indirectly tethering a person to a frame or other device to prevent falls. These have been directed to the medical, gymnastic, railroad, and construction fields, as described hereinbelow. For example, U.S. Pat. No. 2,871,915, issued Feb. 3, 1959 to Hogan, is entitled "ORTHOPEDIC DEVICE." The patent teaches an orthopedic device comprising a load-bearing frame with four telescoping legs connected at their tops by side rails. A lockable caster is attached to each leg. The top is rectangular in shape. A track formed by a pair of cooperating beams extends between the short side rails intermediate the long side rails. A chain, driven by a motor, seats in the track. A body harness is attached to the chain. In use, a person is placed in the body harness, the height of the legs is adjusted, and the person walks along the frame supported by the body harness and pulled by the motor.
U.S. Pat. No. 3,379,439, issued Apr. 23, 1968 to Sorenson et al., is entitled "SIDE HORSE TRAINING DEVICE." The patent teaches a training device comprising a gymnastic "side horse" device and a load-bearing frame suspended above the side horse from cables attached to a ceiling of a room. The frame is movable on the cables. A body harness is attached to, and movable on, the frame. In use, a person is attached to the body harness to facilitate more efficacious use of the side horse.
U.S. Pat. No. 4,607,724, issued Aug. 26, 1986 to Hillberg, is entitled "SAFETY APPARATUS FOR ROOFERS." The patent teaches a safety apparatus comprising a boom pivotally connected to a rotatable stanchion. The stanchion is supported on a roof by an adjustable saddle. A tether is slidably attached at one end to the boom and at the other end to a worker's safety belt or body harness.
U.S. Pat. No. 4,699,245, issued Oct. 13, 1987 to Benedet, is entitled "SAFETY DEVICE FOR WORKING AT GREAT HEIGHTS." The patent teaches a safety device comprising a fixed stanchion and a cable spooling out from it, with a traveler slidable along the cable. The cable attaches to a worker's safety belt or body harness at the end opposite the fixed stanchion.
U.S. Pat. No. 5,143,170, issued Sep. 1, 1992 to Hunt et al., is entitled "SAFETY DEVICE FOR ROOF WORK." The patent teaches a safety device comprising two spaced pairs of mating interlocking sleeper bars positionable over the cap or peak of a roof, straddling the roof. A pair of connecting bars or rods extends between the pair of spaced sleeper bars. The sleeper bars and the connector bars therefore lie flat against the roof. A cable is slidably attached at one end to one of the connector bar and at the other end is connectable to a worker's safety belt or body harness.
U.S. Pat. No. 5,522,472, issued Jun. 4, 1996 to Shuman, Jr. et al., is entitled "FALL PROTECTION SYSTEM FOR BRIDGE CONSTRUCTION." The patent teaches a fall protection system comprising a plurality of generally T-shaped cable supports securable to concrete support columns of a bridle or overpass during bridge construction. A plurality of first cables extend between the plurality of supports. A traveler is slidably attached to each of the plurality of first cables. A second cable extends from each traveler and is securable to a worker's safety belt or body harness.
U.S. Pat. No. 5,537,933, issued Jul. 23, 1996 to Ablad, is entitled "SEGMENTED SAFETY RAIL WITH A MOVABLE TROLLEY." The patent teaches a safety rail for use on a train. The safety rail comprises a plurality of rail segments connected to each other and disposed horizontally on the roof of a train car. A trolley rides on wheels on the rail segments. A cable may be attached to the trolley and, at its other end, to a worker's safety belt or body harness.
What is needed, and what is not provided by the prior art, is an overhead safety frame to which a worker can be secured while both maintaining freedom of movement for the worker and greatly reducing the possibility of tangling or cutting the line used to secure the worker to the frame. Such a frame would promote safety, convenience, and comfort for the worker, while, at the same time, increasing productivity. The present invention is directed to this combination of desirable attributes.